ArcGIS API for Silverlight代码中使用Template模板

本文主要是介绍ArcGIS API for Silverlight代码中使用Template模板，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

在项目开发中，会遇到点选中聚焦闪烁效果，但是因为在使用Symbol的时候，会设置一定的OffSetX和OffSetY，所以聚焦闪烁的时候，有些情况下，会出现闪烁点的位置和Symbol的位置不重叠现象，下面的方法就是解决这个问题的。

1、在Silverlight项目中新建一个文件夹Template，新建一个DefaultMarkerSymbol.xaml的Silverlight资源字典文件，如下图：

2、打开DefaultMarkerSymbol.xaml文件，删掉里面的内容，拷贝如下的内容：

<ControlTemplatexmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"xmlns:vsm="clr-namespace:System.Windows;assembly=System.Windows"xmlns:esri="http://schemas.esri.com/arcgis/client/2009"><Canvas><vsm:VisualStateManager.VisualStateGroups><vsm:VisualStateGroup x:Name="CommonStates"><vsm:VisualState x:Name="Normal"><Storyboard RepeatBehavior="Forever"><DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.RenderTransform).(ScaleTransform.ScaleX)" From="1" To="5" Duration="00:00:01" /><DoubleAnimation BeginTime="0:0:0" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.RenderTransform).(ScaleTransform.ScaleY)" From="1" To="5" Duration="00:00:01" /><DoubleAnimation BeginTime="00:00:00" Storyboard.TargetName="ellipse" Storyboard.TargetProperty="(UIElement.Opacity)" From="1" To="0" Duration="00:00:01" /></Storyboard></vsm:VisualState></vsm:VisualStateGroup></vsm:VisualStateManager.VisualStateGroups><Ellipse Height="25" Width="25" Canvas.Left="0" Canvas.Top="0" RenderTransformOrigin="0.5,0.5" x:Name="ellipse" IsHitTestVisible="False"><Ellipse.RenderTransform><ScaleTransform /></Ellipse.RenderTransform><Ellipse.Fill><RadialGradientBrush><GradientStop Color="#00FF0000" /><GradientStop Color="#FFFF0000" Offset="0.25" /><GradientStop Color="#00FF0000" Offset="0.5" /><GradientStop Color="#FFFF0000" Offset="0.75" /><GradientStop Color="#00FF0000" Offset="1" /></RadialGradientBrush></Ellipse.Fill></Ellipse><Ellipse Height="20" Width="20" Canvas.Left="0" Canvas.Top="0" Fill="#FFFF0000" x:Name="ellipse1" /></Canvas>
</ControlTemplate >

3、Silverlight程序代码中使用，这里是通过选中ListBox中的站点名称，进行聚焦显示，方法如下：

 private void lbSearchSite_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e){RainFall findResult = e.AddedItems[0] as RainFall;Graphic g = new Graphic(){Geometry = mercator.FromGeographic(new MapPoint(double.Parse(findResult.Latitute.ToString().Trim()), double.Parse(findResult.Longitute.ToString().Trim())))};MarkerSymbol symbol = new MarkerSymbol();string contentStr = new StreamReader(Application.GetResourceStream(new Uri("/MapClient;component/Template/DefaultMarkerSymbol.xaml", UriKind.Relative)).Stream).ReadToEnd();symbol.ControlTemplate = (ControlTemplate)XamlReader.Load(contentStr);symbol.OffsetX = 10;symbol.OffsetY = 10;g.Symbol = symbol;ESRI.ArcGIS.Client.Geometry.Envelope selectedFeatureExtent = mercator.ToGeographic(g.Geometry).Extent; //选中点的位置double expandPercentage = 10;//加数值后，聚焦（这里需要注意，进行地理坐标和墨卡托坐标的转换）double widthExpand = (selectedFeatureExtent.Width + 5) * (expandPercentage / 100);double heightExpand = (selectedFeatureExtent.Height + 5) * (expandPercentage / 100);ESRI.ArcGIS.Client.Geometry.Envelope displayExtent = new Envelope(WKIDConvert.lonlat2mercator(new MapPoint(selectedFeatureExtent.XMin - (widthExpand / 2), selectedFeatureExtent.YMin - (heightExpand / 2))), WKIDConvert.lonlat2mercator(new MapPoint(selectedFeatureExtent.XMax + (widthExpand / 2), selectedFeatureExtent.YMax + (heightExpand / 2)))){SpatialReference = new SpatialReference(102100)};try{//聚焦myMap.ZoomTo(displayExtent);ShowFocus(g);}catch (Exception){}}/// <summary>/// 显示聚焦点/// </summary>public void ShowFocus(Graphic g){GraphicsLayer graphicsLayerSW = myMap.Layers["GraphicsLayerRed"] as GraphicsLayer;//产生红色光晕if (graphicsLayerSW.Graphics.Count < 1){graphicsLayerSW.Graphics.Add(g);}else{graphicsLayerSW.Graphics.RemoveAt(0);graphicsLayerSW.Graphics.Add(g);}}

4、效果图如下：